Valve control system



J. P. KRIECHBAUM VALVE CONTROL SYSTEM Filed Ma 5, 1934 July 21, 1936.

wv nv M QEQM F 3 3 mm .mg m m ow 3 mm m. Km NN P n Patented July 21,.1936 VALVE coN'raoL srs'rnm John P. Kriechbaum, Minneapolis, Minn, as-,signor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., acorporation of Delaware Application May 5, 1934, Serial No. 724,146

16 Claims. (Cl. 23674) The present invention relates to an automaticcontrol system'by which a plurality of valves may be controlled and hasparticular utility in connection with the control of a plurality of 5valves whichcontrol the supply of fuel to a heating device such as a gasburner.

One ofzthe :objects of the present invention is the provision of acontrol system, including a member movable back and forth along 'apredeltermined path vof travel in response to changes in a condition, togetherwith means by which the control member sequentially opens a plurality ofvalves upon-changes in the value of acondition to, which theimovablemember responds and se- 15 quentially closes the valves upon restorationof said condition, the'arrangement being such that each of the valves isclosed at a different value of the condition than that at which they.are opened.

- 2 In controlling the supply of fuel to a. burner and particularly toagas burner, it is often desired to initially supply a relatively smallamount of fuel upon small deviations of the value of the controllingcondition. However, most gas burn- 25 ers while allowing a relativelygreat throttling of the gas supply when the burner is already inoperation require a larger initial supply of gas thereto in order togive proper ignition. As a result, the initial supplyof gas mustberelatively large and it often happens that this large initial supplyof gas is larger than it is desired to burn continuously until the valueof the controlling condition has deviated from the desired value by aconsiderable amount. It has there- 35 fore been proposed to provide anarrangement whereby upon a demand for a relatively small amount of fuel,a large a'mountof fuel will be momentarllysupplied to provide for properignition and thereafter the supply of fuel will be decreased-toan'amount corresponding to the demand. Thepresent invention provides animproved-system whereby such operation may be obtained."

A -further object *of'the'invention is the provi- 5- sion=of 'a'controlsystem by which a pair of valves are'moved to openposition upon a demandfor a relatively-sm'all flow of fluid. together with means controlled bymovement of one of the valves *tdopen position for-closing the other of56 the valves whereby one of the valves is momentarily opened to providea' large initial flow of fluid and is then quickly closed'to reduce theflow of fluid to an amount corresponding to the demand. The valves arepreferably of the 55' electrically operated type and the momentary meanscontrolled by the first valve when moved to open position for closingthe second valve, 0 together with means for again opening the secondvalve and maintaining the same open upon an increase in the demand forfluid flow.

Other objects of the invention include the provision of a completesystem of the class above described which system includes a single-pilotswitch responsive to the condition of a pilot burner' for igniting amain burner the flow of fuel "to which is controlled by a pair of valvesone of which is momentarily opened upon an initial demand for a smallamount of fuel.

Another object of the invention'comprises the provision ofa system ofthe nature-defined above in which all of the apparatus and particularlythe two valves are standard equipment readily available on the marketand are arranged, by the simple addition of a single switch controlledby one of the valves, to give a momentary opening of the other of thevalves upon an initial demand for a relatively small flow of fuel to theburner. I

Other objects of the invention will be found in the followingdescription, the accompanying drawing and the appended claims.

v is connected to ,a gas supply main II by means of branch pipes l2 andI3. The flow of gas through gas pipe I! is controlled by a firstelectrically operated valve l4 and the flow of gas through the branchpipe I! is controlled by a second electrically operated'valve I 5. Thegas issuing from main burner Ill is adapted to be ignited by a pilotburner it which is connected to gas'main II by means of a pilot pipe i1.

The electrically opera-ted'valves l4 and I! are .diagrammaticalrepresentations of commercial valves of well-known construction and bothof these valves are identical in their details. The valves l4 and i5include .valve stems- 26 and 20awhich are normally biased to valveclosing position by means of coiled springs 2| and 2|a.

The-valve stems 20 and 20a are adapted to be lifted against the bias oftheir springs 2| and 2 la by means oflevers 22 and 221: which arepivoted at pointsindicated at 23 and 23a. The valve i4 is operated by arotary electrical motor 24 which comprises a field winding 25 and arotor 26. Rotor 26 drives a gear 21 through a gear and .pinion assembly28 and a rotor pinion 23. Valve I5 is operated by a'motor 24a whichcom-' prises a field winding 25a and a rotor 26a. Rotor 26a is adaptedtodrive a gear 21a through a gear and pinion assembly 28a and a rotorpinion 29a.

The gears 21 and 21a respectively carry crank and 2|a close the valvesl4 and l5 and rotate the gears 21 and 21a. and the other gears andpinions associated therewith, as well as the motor rotors, in thereverse direction.

The gears 21 and 214 are carried upon shafts 33. and 331: which operatecams 34 and 34a through suitable slip friction connecting means.

Referring to Fig. 2 of the drawing, it will be seen that the shaft 33 isprovided with .a collar against which the cam 34 is pressed [by means ofa coiled spring 36. .Washers 31 are interposed between coiled spring 36and cam 34 and between collar 35 and cam 34. The other end of the coiledspring 36 is confined against longireceived in a suitable opening inshaft 33. The

in its movement, the slip frictional connection above described willallow continued movement of shaft 33. The cam 34a is connected to shaft33a. through a similar slip friction connecting means.

. 4 Cams 34 and 34a are provided with notches 40 and 40a whichcooperatewith stop pins 4| and Ma, whereby the movements of cams 34 and34a are/restricted. Cam 34 operates a switch arm 43fwhich is-adapted tobe moved into engagement witha stationary contact 44 but is normallybiased from engagement therewith by means of a spring 45. Similarly,cam-34a is adapted to operate a switch arm 43a that is movable intoengagement with a contact 44a but is normally biased from engagementtherewith by means of a spring 45a. Stop pins 46 and 46a limit themovement of switch arms 43 and 43a away from their cooperating contacts44 and 44a. The switch arm 43 and contact 44 comprise a first holdingswitch and the switch arm 43a and contact 44a comprise a second holdingswitch. From an inspection of the drawings, it will be noted that thearrangement is such that upon initial movement of cam 34 in clockwisedirection, switch arm 43 will be moved into engagement with contact 44.The stop pin 4| will thereafter prevent further clockwise rotation ofcam 34 and, about this time, crank pin 30 will engage hooked link 3| tobegin raising valve stem 26 of valve M. The holding switch comprised byswitch arm 43 and contact 44' istherefore closed upon initial movementof gear 21 in valve opening direction. Similarly, the sec- Y ond holdingswitch comprised by switch arm" 43aand contact 440. is moved to closedposition upon initial movement of gear 21a in valve opening direction.

'Valves l4 and I5 are hereinshown as controlled by a' conditionresponsive element in the form of a bimetallic element 50 which respondsto the temperature of a room or space to be heated. One end of thebimetallic element 56 is held stationaryand the other end thereofconengages switch arm 56 and lastly switch arm 5| disengages contact 55.

Power for field winding 25 is supplied by a step-down transformer 59,having a low voltage secondary 60 and a high voltage primary 6|connected to suitable-line wires 62 and 63. The ca-:

pacity of the transformer-53 is suihcient to operate motor 24 but isinsuflicient to additionally operate motor 24a. Power for motor 24a issupplied by a similar transformer 64, having a low voltage secondary 65and a high voltage primary 66 which is also connected to the line wires62 and 63. The system also preferably includes a pilot switch comprisedby a bimetallic element 61 which engages a contact 68 whenever thepilot. burner I6 is operating properly. Such pilot switches are wellknown in the art. 9' th. e

The lever 22 supports a mercury switch arrangement being such thatmercury switch 63 is moved to open position only when valve l4 has beencompletely or substantially completely opened and is closed at all othertimes.

The remaining circuit connections will be described in detail under theheading fOperation".

Operation with the parts in the position shown, the room temperature isat or above the desired point so that both, the first and second gasvalves l4 and I5 are closed. The main burner I4 is inoperativev but thepilot bumer I6 is operating properly as indicated by the fact thatbimetallic element "61 is engaged with its contact 66.

Now as the room temperature falls, switch arm 5| will engage contact butsuch engagement of switch arm 5| with contact 55 does not complete anyinitial energizing circuits.. Upon further fall in space temperature,switch arm 52 will engage contact 56 whereupon fleld windings 25 and 25awill be simultaneously energized.

The circuit for fleld'winding 25 is as follows:

secondary of transformer 53,' wire 16,- bi- 52', contact 56, wire 12,wire 13, wire 14, field winding 25, and wire 15 to the other side ofsecondary 60. The energizing circuit for field winding 25a is asfollows: secondary 65 of transformer 64, wire 15, wire 10. bimetallicelement 51, contact 68, wire 1|, bimetallic element 50', switch arm 5|,switch arm 52, contact 56, wire 12, wire 11, mercury switch 69, wire 18,wire 19, field winding a, and wire 80 to the other side of secondary 55.

Gears 21 and 21a will thereupon be rotated in clockwise direction. Thefirst and second holding switches comprised by switch arms 43 and 43aand contacts 44 and 44a will first be closed in the manner heretoforedescribed. Engagement of switch arm 43 with contact 44 establishes aholding circuit for field'winding 25 as follows: secondary 60, wire 10,bimetallic element 61, contact 58, wire 1|, bimetallic element 5|),switch arm 5|, contact 55, wire 8|, contact 44, switch arm 43, wire 82,wire 14, 'field winding 25 and wire 15 to secondary 50. Engagement licelement 50, switch arm 5|, contact 55, wire toward open position. whenvalve I4 is completely or substantially completely opened, mercuryswitch 69 will be moved to open circuit position whereby the energizingcircuit for field winding 25a will be interrupted. Valve l5 willtherefore close and its holding switch will be returned to the openposition shown in the drawing. Valve It will remain in its open positionby reason of stalling of its motor 24 and will remain in such openposition until switch arm5| disengages contact 55. i

From the foregoing description, it will be seen that upon an initial.fall in room temperature,

' demanding a relatively small fiow of gas, both flow of gas to the mainburner ||i which fiow of gas is reduced in accordance with the demandsby the closing of valve l5. The large flow of gas produced by thecombined openings of valves l4 and i5 provides a full fiow of gas tomain burner l0 which is readily ignited by the pilot burner l6.After'the main burner I0 is placed inoperation, the reduced fiow of gasallowed by valve l4 will remain burning properly since ignition hasalready been established.

If there should be a continued fall inroom temperature so as to bringswitch arm 53 into engagement with contact 51 and then bring switch arm54 into engagement with contact 58, field winding 25a. of gas valve l5willagain be energized by a circuit as follows: secondary 65. wire 15,wire 10, bimetallic element 51; contact 68, wire 1|, bimetallic element55, switch arm 5|, switch arm 54, contact 58, wire 83, wire 19, fieldwinding 25:: and wire 80 to the other side of secondary 55. The holdingswitch comprised by switch arm 43a and contact 44:: will be quicklyclosed as previously explained and will establish a holding circuit forfield winding 25a as follows: secondary 65, wire 15, wire 10, bimetallic51, wire 84, contact 44a, switch arm 43a, wire 85,. field winding 251aand wire 80 to the other side of secondary 55. The gas valve I5 istherefore moved to open position upon a further fall in room temperatureso as to again give a full supply of gas to the main burner l0. Valve l5will now remain open until the roomtemperature is restored suflicientlyto move switch arm 54 from engagement with contact 58, thereby breakingthe energizing circuit for field winding 25a, and until switch arm 53disengages contact 51 whereupon the holding circuit for field winding25a is interrupted. When the room temperature has thus been partiallyrestored and both the energizing and holding circuits for field winding25a are interrupted, valve l5 will close and its controlling mechanismwill return to the position shown in the drawing. If the roomtemperature should thereafter again decrease so as to bring switch arms53 and 54 into engagement with contacts 51 and 58, gas valve l5 willagain be energized as previously explained. However, if the roomtemperature continues to increase, switch arm 52 will move fromengagement with contact 58 and interrupt the energizing circuit for gasvalve |4. Gas valve M will remain open however until the roomtemperature is completely restored so as to move switch arm 5| fromengagement with contact 55 to interrupt its holding circuit. 30

If the pilot burner l6 should become extinguished at any time, the pilotswitch defined by 81-58 will open and prevent opening of gas valves i4and I5 or prevent their remaining open if they should be open when thisoccurs.

The levers 22 and 22a may. of course operate secondary air dampers inthe usual manner if desired. a

From the foregoing description, it will be seen that the presentinvention provides a simple system utilizing standard parts andrequiring merely the addition of the single mercury switch 65 in orderto provide a system wherein two valves are simultaneously opened upon ademand for a small flow of fluid and one of them is thereafterimmediately closed whereby a large initial supply of fiuid is providedand the supp y is then reduced in accordance with the demand.Furthermore, if there should thereafter be a demand for a larger supplyof fluid, the second valve is again opened and maintained open. Further,it will be noted that the first and second valves are sequentiallyopened upon changes in the value of a condition in one direction and aresequentially closed upon restoration of the condition but at values ofthe condition which are diflercnt than those at which the valves wereopened.

It is obvious that the invention is applicable to systems other thanthat disclosed herein and that many changescan readily be made by those60 1. In combination, a movable member adapted to move back and forthalong a predetermined path of travel, a first valve, a second valve,connections between said member and first valve for opening the'latterwhen said movable member reaches a first point in its path of travelwhile moving in a first direction and'for closingthe same when saidmovable member reaches a second point-in traveling in a seconddirection, connections between both of said valves and said -movablemember for also opening said second.

valve when the-movable -member reaches said travel when moving in saidfirst direction and for closing said second valve when said movablemember-reaches a fourth point in its path of travel upon movement insaid second direction,

all four of said points being spaced one from another.

2. In combination, a movable member adapted to move along apredetermined path of travel, first and second valves, and connectionsbetween said movable member and valves for opening said first and secondvalves at a first point, then closing said second valve, and for againopening said second valve at a second point as said movable member movesalong its path of travel in one direction and for closing said secondand first valves when said movable member reaches third and fourthpoints in its path of travel upon return movement of said movablemember, said movable member passing through said third and fourth pointsin moving to said first and second points when moving in said firstdirection.

3. In combination, first and second switches, means responsive to acondition for sequentially closing said switches in the order named uponcontinued change of said condition in a single direction, a firstelectrically operable valve, a third switch moved to open position bysaid valve when the valve reaches open position, a second electricallyoperable valve, an energizing circuit for said first valve controlled bysaid first switch, an energizing circuit for said second valvecontrolled by said first switch and third switch in series whereby saidsecond valve is opened momentarily. upon closure of said first switch, asecond energizing circuit for said second valve controlled by said thirdswitch and holding circuits for said valves controlled by said conditionresponsive means.

- 4. In combination, means responsive to the value of'a condition, threeswitches sequentially closed thereby upon continued change of saidcondition in one direction, a first electrically operable valve, afourth switch which is closed and a fifth switch which is opened by saidfirst valve upon opening thereof, an energizing circuit for said firstvalve controlled by said second switch, a holding circuit for saidfirstvalve controlled by said first and fourth switches, a secondelectrically operable valve, a first energizing circuit'thereforcontrolled by said second and fifth switches in series, and a secondenergizing circuit for said valve controlled by said third switch.

5. In combination, means responsive to the value of a condition, fourswitches sequentially closed thereby upon a change in said condition ina single direction, a first electrically operable valve, a fifth switchmoved to open position and a sixth switch moved to closed position bysaid valve upon opening thereof, a second electrically operable valve, aseventh switch closed by the second valve when opened, an energizingcircuit for said first valve controlled by said second switch, .an'energizing circuit for said second valve controlled by said second andfifth switches in series whereby said second valve is opened momentarilyuponclosure of said second switch, a holding circuit for said firstvalve controlled by said first and sixth switches, a second energizingcircuit for said second valve controlled by said switches in series.

6. In combination, a condition responsive switch, a first electricallyoperable valve, 9. second switch, means associated with said first valveand second switch by which the second switch is moved to open positionas a result of opening of said first valve, a second electricallyoperable valve, first and second transformers for said first and secondvalves, each transformer having sumcient capacity to operate itsrespective valve but insufilcient capacity to operate. both of said Ivalves, a circuit comprising said first transformer, conditionresponsive switch, and first valve, and a circuit comprising said secondtransformer; condition responsive switch, second switch and secondvalve.

'7. The combination with a. heating system comprising first and secondelectrically operable valves controlling the supply of fuel to a mainburner and a pilot burner for igniting the main burner, of a controlsystem for said valves, comprising, in combination, a pilot switch, amain control switch, a third switch moved to open position by said firstvalve when opened, a first transformer having sufilcient capacity tooperate a only said first valve, a second transformer having sufficientcapacity to operate only'said second valve, a circuit comprising saidfirst transformer. first valve, pilot switch and main 'control switchand a circuit comprising said second transformer, second valve, pilotswitch, main control switch and third switch.

8. A heating system of the class described, comprising in combination,first and second electrically operated gas valves for controlling thefiow of gas to a burner for heating a space, a space temperatureresponsive thermostatic element, four control switches sequentiallyclosed thereby upon temperature fall, first and second holding switchesrespectively closed by said first and second gas valves when energized,a valve operated switch moved to open position by said trolled by saidthird control switch and second holding switch in series. v

9. In combination, means responsive to the value of a condition, threeswitches sequentially closed thereby upon continued change of saidcondition in one direction, first and second elec trically operablevalves, a fourth switch which is opened by said first valve upon openingthereof, a fifth switch which is closed by said second valve uponopening thereof, an energizing circuit for the first valvecontrolled bysaid first switch, a first energizing circuit for the second valvecontrolled by the first switch and fourth switch in series, a secondenergizing circuit for the second valve controlled by the third switch,and a holding circuit for the second valve controlled by the secondswitch and fifth switch in series.

10. In a valve controlling system, in combination, a first valveincluding motor means in control thereof, a second valve includingentirely able to close said second valve upon opening of a said firstvalve.

11; In a valve controlling system, in combina-, tion, a first valveincluding motor means in con trol thereof, a second valve includingentirely separate and independent motor means in control thereof, acontrol member in control of the motor means of both valves operable tocause simultaneous opening of both of said valves, control meansactuated, by said first valve in control of the motor means of thesecond valve operable to close said second valve upon opening of saidfirst valve, and a second control member in controlof said second valvemotor operable to open the second valve independently of the conditionof said control means. 1

12 In an electrical valve controlling system, in combination, a firstvalve including electric motor means in control thereof, a second valveincluding a separate electric motor means in control thereof, a firstcontrol switch, circuit connections for the motor means of both valvescontrolled by said first control switch operable to open both valvesupon closure of the first control switch, and switching means operatedby said first valve which causes closure of the secondvalve upon openingmovement of said first valve.

13. In an electrical valve controlling system, in

combination, a first valve including electric motor means in controlthereof, a second valve including a separate electric motor means incontrol thereof, a first control switch, circuit connection for themotor means of both valves controlled by said first control switchoperable to' open both valves upon closure of the first control switch,

switching means operated by said first valve which causes closure, ofthe second valve upon opening movement of said first valve, a secondcontrol switch, and circuit connections controlled thereby for the motormeans of said second valve to cause opening thereof upon closure of thesecond control switch.

' 14. In an electrical valve controlling system, in

said first control switch operable to open both valves upon closure ofthe first control switch, switching means operated by said first valvewhich causes closure of the second valve upon opening movement of saidfirst valve, 2. second control switch, circuit connections controlledthereby for the motor means of said first valve to cause opening thereofupon closure of the second control switch, and a movable memberresponsive to a condition which sequentially closes said first andsecond control switches.

15. In a valve controlling system, in combina tion, a first valvecomprising means to bias the same to closed position and an electricmotor to open the same and hold it open against its bias when energized,a second separate valve including separate biasing means which biasesthe same. to closed position and a separate electric motor to open thesame and maintain it open against its bias when energized, a firstcontrol switch, energizing circuits for each of the motors of said'valves completed by closure of said first control switch, a secondcontrol switch in the circuit for the motor ofthe second valve,connections between the first valve and second control switch to openthesecond control switch upon opening movement of said first valve, a thirdcofitrol switch, and a; separate energizing circuit for the motor ofsaid second valve controlled by said third control switch independentlyof said second concompleted by closure of said first control switch,

a second control switch in the circuit for the motor of the secondvalve, connections between the first. valve and second control switch toopen the second control switch upon opening movement of said firstvalve, a third control switch, a separate energizing circuit for themotor of said second valve controlled by said third control switchindependently" of 'said secondcontrol switch, and a single conditionresponsive member to sequentially close said first and third controlswitches. V

' JOHN P. KRIECHBAUM.

